Nano combined heat and power plant

Good evening, we are looking for an energy concept for our detached house (new build/start: 2017 / 150sqm). I am currently reading a lot about the nano combined heat and power unit. Our energy consultant said in the first phone call that it would not be the right thing for our concern because it is too expensive and the generated heat would not be used up (e.g. in summer). Does anyone have experience with this? Yes, it is expensive, but doesn't it pay off over time? Then you could also do without solar additionally, right?

I believe we also thought about it at one point... but it really moved far beyond everything in terms of costs – always keep in mind that the time of €1500 annual heating costs is over – new buildings are sometimes at one third of that; investment costs are very much in the foreground.